Hi, New here! (Carb questions)

[Ardfarkl]

I am looking for the jettin gguru. I live in San Antonio, TX. Just finished building a 2005 YZ 144. It was built for race gas. I am currently using VP's C-12. I went up on the main jet to a 420 and dwon on the clip one position. Still seems a little rich.

Now the real issue. I am going to VP's U2. I am already rich, but I am told U2 will lean it out. I need a good jetting marker to start from . I was told that the main and pilot jet would have to be changed, but to what? I never was good at this part.

Thasnks for any help ahead of time.

[FPMXer]

Welcome to E2S. If it's rich now I would leave it the way it is and install a new plug. Run the bike and do a plug chop to see which way to move the jetting.

[Ardfarkl]

Anyone else?? I really appreciate it.

[FPMXer]

The place you had the bigbore kit done with didn't recommend any jetting??? I only went 2mm over on my KX124 and kept the jetting the same. So I would say start +10 from stock on both pilot and main with clip in middle and see what plug looks like.

[kxrider]

i would bump up both ur main and pilot jet a couple of sizes and see how tha plug looks

[Mert]

flotek is the guy to ask, where you live at in SA, I live in New Braunfels and I'm looking for people to ride with.

[Ardfarkl]

Where do you go to ride a quad?

[dajogejr]

Get the bike dialed in on the VP C12. Only change one circuit at a time...or your asking for trouble.

Here's how to dial in your main jet:
http://www.dfn.com/benkaren/plugchop.html

I know the U4 has recommendations on how rich to go once you use it, 2-4 main jet sizes would be my best guess.